US4037244A - Avalanche photodiode - Google Patents

Avalanche photodiode Download PDF

Info

Publication number
US4037244A
US4037244A US05/684,382 US68438276A US4037244A US 4037244 A US4037244 A US 4037244A US 68438276 A US68438276 A US 68438276A US 4037244 A US4037244 A US 4037244A
Authority
US
United States
Prior art keywords
layer
diode
conductivity
layers
type
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US05/684,382
Inventor
Baudouin DE Cremoux
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Thales SA
Original Assignee
Thomson CSF SA
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Thomson CSF SA filed Critical Thomson CSF SA
Application granted granted Critical
Publication of US4037244A publication Critical patent/US4037244A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01LSEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L31/00Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
    • H01L31/08Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof in which radiation controls flow of current through the device, e.g. photoresistors
    • H01L31/10Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof in which radiation controls flow of current through the device, e.g. photoresistors characterised by potential barriers, e.g. phototransistors
    • H01L31/101Devices sensitive to infrared, visible or ultraviolet radiation
    • H01L31/102Devices sensitive to infrared, visible or ultraviolet radiation characterised by only one potential barrier
    • H01L31/107Devices sensitive to infrared, visible or ultraviolet radiation characterised by only one potential barrier the potential barrier working in avalanche mode, e.g. avalanche photodiodes

Definitions

  • This invention relates to an avalanche photodiode intended for telecommunications by optical fibres.
  • Avalanche photodiodes have already been used for this purpose.
  • Avalanche photodiodes add an amplifier effect caused by the avalanche to the photodetector effect.
  • Conventional diodes of this kind are made of silicon or germanium.
  • the object of the present invention is to provide an avalanche photodiode which does not have any of these disadvantages.
  • the avalanche photodiode according to the invention is of the type comprising a heterojunction, one of the elements of the junction being made of a material which is transparent to the wavelength to be detected, the other being opaque to that wavelength.
  • the avalanche photodiode according to the invention is essentially distinguished by the fact that, between the two elements of the junction there is a region which is doped to a greater extent than the transparent element. This region may be the seat of the avalanche phenomenon without affecting the element in which it is present.
  • FIG. 1 is a basic diagram of the diode according to the device.
  • FIG. 2 diagrammatically illustrates a first example of embodiment.
  • FIG. 3 diagrammatically illustrates a second example of embodiment.
  • FIG. 1 is a diagram of an avalanche diode according to the invention. It comprises three superimposed layers 1, 2 and 3, the region 2 extending solely in the central zone of the region 3.
  • the region 1 is heavily doped and is of a first conductivity type
  • zone 3 is lightly doped and is of the conductivity of the zone 2.
  • the end zones 1 and 3 support contacts 6 and 7, respectively, which enable them to be connected to the respective poles of a battery 8, one directly and the other across a load resistance R c .
  • the biassing source 4 biasses the diode in the backward direction.
  • the zone 3 is directly exposed to the radiation to be detected.
  • At least one of the materials 1 and 3 is a material with a forbidden band width greater than that of the material 2 so that it is transparent to the radiation to be detected. In the case of FIG. 1, it is the layer 3 which is subjected to the impact of the radiation.
  • the n-doped layer 1 (doping concentration of the order of 10 16 at/cm 3 ) is deposited upon a substrate 100 of the same conductivity type, this substrate being more heavily doped (10 18 at/cm 3 ).
  • the layer 2 has a p-type conductivity and is heavily doped (10 17 to 10 18 at/cm 3 ).
  • the layer 2 has a thickness of the order of 0.1 micron; this thickness is such that the layer 2 is unable to absorb the radiation to be detected. It is inserted into the zone 3 which has a much lower doping concentration and a thickness to the order of 5 microns.
  • the substrate is earthed.
  • the space charge due to the potential - V biassing the diode in reverse direction is limited by the equipotentials 0 and - V.
  • the greater the doping of one of the elements of the junction the lesser the thickness of the space charge zone. This results in the form of the two equipotentials 0 and - V which surround the zone 2 and approach it.
  • the electrical field is at its maximum at the interface between the region 2 and the region 1.
  • the radiation to be detected passes through the regions 2, 3 and 4 without significant absorption and is absorbed by about 1 micron in thickness in the region 1.
  • Each photon creates one pair of electron-hole. Since the potential - V is assumed to be sufficient to obtain the avalanche in the region 2 and not in the region 3, each electron travels towards earth. By contrast, the holes pass through the zone 2 where they trigger off the avalanche phenomenon.
  • the advantage of initiating the avalanche by the holes is that the noise caused by the amplification phenomenon is lower than in the case where it is initiated by the electrons.
  • the conductivity types are reversed, the substrate 100 being of the p +- type (doping concentration 10 18 at/cm 3 ).
  • the layer 1 is of the p - type and has a thickness of the order of 10 microns.
  • the layer 2 has a much greater thickness than in the previous case (1 to 2 microns) and an n - conductivity type and a doping concentration of the order of 10 16 at/cm 3 .
  • the layers 3 and 4 are of type n - and type n + conductivity, respectively (doping concentration 10 15 and 10 19 at/cm 3 , respectively) and have the same thickness (5 microns, for example).
  • a potential + V is applied to the contact 6.
  • the radiation is thus absorbed by the layer 2 itself and the field is at its maximum in the vicinity of the interface of the regions 1 and 2.
  • the various materials used have a composition corresponding to the formula Ga 1 -x Al x As, with 0 ⁇ x ⁇ 0.2.
  • the diodes are obtained by liquid-phase epitaxy as described in U.S. patent application Ser. No. 526,929.

Landscapes

  • Physics & Mathematics (AREA)
  • Condensed Matter Physics & Semiconductors (AREA)
  • Electromagnetism (AREA)
  • General Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • Computer Hardware Design (AREA)
  • Microelectronics & Electronic Packaging (AREA)
  • Power Engineering (AREA)
  • Light Receiving Elements (AREA)

Abstract

An avalanche photodiode has an avalanche voltage relatively low. In one of the two elements of the junction there is a zone doped more heavily than said element and having the same conductivity type.

Description

This invention relates to an avalanche photodiode intended for telecommunications by optical fibres.
Avalanche photodiodes have already been used for this purpose. Avalanche photodiodes add an amplifier effect caused by the avalanche to the photodetector effect. Conventional diodes of this kind are made of silicon or germanium.
They have the disadvantage of necessitating a high avalanche voltage of the order of 200 volts and of having a low performance at the wavelength of 0.80 microns which is particularly used in telecommunications.
The object of the present invention is to provide an avalanche photodiode which does not have any of these disadvantages.
The avalanche photodiode according to the invention is of the type comprising a heterojunction, one of the elements of the junction being made of a material which is transparent to the wavelength to be detected, the other being opaque to that wavelength. The avalanche photodiode according to the invention is essentially distinguished by the fact that, between the two elements of the junction there is a region which is doped to a greater extent than the transparent element. This region may be the seat of the avalanche phenomenon without affecting the element in which it is present.
The invention is described in more detail in the following with reference to the accompanying drawings, wherein:
FIG. 1 is a basic diagram of the diode according to the device.
FIG. 2 diagrammatically illustrates a first example of embodiment.
FIG. 3 diagrammatically illustrates a second example of embodiment.
FIG. 1 is a diagram of an avalanche diode according to the invention. It comprises three superimposed layers 1, 2 and 3, the region 2 extending solely in the central zone of the region 3. The region 1 is heavily doped and is of a first conductivity type, zone 3 is lightly doped and is of the conductivity of the zone 2. The end zones 1 and 3 support contacts 6 and 7, respectively, which enable them to be connected to the respective poles of a battery 8, one directly and the other across a load resistance Rc.
The biassing source 4 biasses the diode in the backward direction. The zone 3 is directly exposed to the radiation to be detected.
At least one of the materials 1 and 3 is a material with a forbidden band width greater than that of the material 2 so that it is transparent to the radiation to be detected. In the case of FIG. 1, it is the layer 3 which is subjected to the impact of the radiation.
Two arrangements are possible, namely the arrangements shown in FIGS. 2 and 3 in which the phenomena are not strictly identical.
In the first case, FIG. 2, the n-doped layer 1, (doping concentration of the order of 1016 at/cm3) is deposited upon a substrate 100 of the same conductivity type, this substrate being more heavily doped (1018 at/cm3). The layer 2 has a p-type conductivity and is heavily doped (1017 to 1018 at/cm3). The layer 2 has a thickness of the order of 0.1 micron; this thickness is such that the layer 2 is unable to absorb the radiation to be detected. It is inserted into the zone 3 which has a much lower doping concentration and a thickness to the order of 5 microns. A zone 4 of p+ type (doping concentration 1019 at/cm3), of the order of 5 microns thick, covers the assemblage and carries a contact 6 brought to a potential - V. The substrate is earthed.
The arrangement operates as follows:
The space charge due to the potential - V biassing the diode in reverse direction is limited by the equipotentials 0 and - V. In this case, it is known that the greater the doping of one of the elements of the junction, the lesser the thickness of the space charge zone. This results in the form of the two equipotentials 0 and - V which surround the zone 2 and approach it.
The electrical field is at its maximum at the interface between the region 2 and the region 1.
The radiation to be detected passes through the regions 2, 3 and 4 without significant absorption and is absorbed by about 1 micron in thickness in the region 1. Each photon creates one pair of electron-hole. Since the potential - V is assumed to be sufficient to obtain the avalanche in the region 2 and not in the region 3, each electron travels towards earth. By contrast, the holes pass through the zone 2 where they trigger off the avalanche phenomenon.
The advantage of initiating the avalanche by the holes is that the noise caused by the amplification phenomenon is lower than in the case where it is initiated by the electrons.
In FIG. 3, the conductivity types are reversed, the substrate 100 being of the p+- type (doping concentration 1018 at/cm3). The layer 1 is of the p- type and has a thickness of the order of 10 microns. The layer 2 has a much greater thickness than in the previous case (1 to 2 microns) and an n- conductivity type and a doping concentration of the order of 1016 at/cm3.
The layers 3 and 4 are of type n- and type n+ conductivity, respectively ( doping concentration 1015 and 1019 at/cm3, respectively) and have the same thickness (5 microns, for example).
A potential + V is applied to the contact 6. As in the previous case, this results in reverse biassing of the diode, but the space charge region penetrates (equipotential + V) into the region 2 by virtue of its much greater thickness than in the previous case. The radiation is thus absorbed by the layer 2 itself and the field is at its maximum in the vicinity of the interface of the regions 1 and 2.
The holes created by the impact of the photons are entrained towards earth and bring about the avalanche in the region 2, as in the previous case. In both cases, the figures quoted are based on a radiation λ of wavelength substantially equal to λ = 0.8 μ (infrared).
The various materials used have a composition corresponding to the formula Ga1 -x Alx As, with 0 < x < 0.2.
The diodes are obtained by liquid-phase epitaxy as described in U.S. patent application Ser. No. 526,929.
The characteristics of two examples described purely by way of illustration are summarised in the following Tables:
                                  TABLE 1                                 
__________________________________________________________________________
EXAMPLE 1                                                                 
REGION    SUBSTRATE                                                       
                   1    2    3    4                                       
__________________________________________________________________________
thickness 500      5    0.1  5    5                                       
(μ)                                                                    
x         0        0    0 or 0.2  0.2                                     
                        0.2                                               
impurity type                                                             
          n        n    p    p    p                                       
 ##STR1## 10.sup.18                                                       
                   #10.sup.16                                             
                         ##STR2##                                         
                             <10.sup.15                                   
                                  >10.sup.19                              
purpose   --       detec-                                                 
                        amplifi-                                          
                             --   con-                                    
                   tion cation    tact                                    
__________________________________________________________________________
                                  TABLE 2                                 
__________________________________________________________________________
EXAMPLE 2                                                                 
REGION    SUBSTRATE                                                       
                   1    2    3    4                                       
__________________________________________________________________________
thickness 500      10   1 to 5    5                                       
(μ)                  2                                                 
x         0        0    0    0.2  0.2                                     
type of con-                                                              
ductivity p        p    n    n    n                                       
 ##STR3## >10.sup.18                                                      
                   10.sup.18                                              
                        10.sup.16                                         
                             10.sup.15                                    
                                  10.sup.19                               
purpose                 Detection contact                                 
                        and                                               
                        amplifi-                                          
                        cation                                            
__________________________________________________________________________

Claims (8)

What I claim is:
1. An avalanche photodiode for detecting incident radiation of a predetermined wavelength comprising superimposed, a first layer of a first type of conductivity and a second layer of a second type of conductivity opposite to the first, said layers having respective superimposed central portions, and inserted in one of said central portions a third layer forming a rectifying junction with said first layer, said third layer having a high impurity concentration, so that the electrical avalanche phenomenon is localized preferentially in said third layer for reverse biasing predetermined voltage values applied to said diode.
2. A diode as claimed in claim 1, wherein said second layer is exposed to said radiation, and being made of a semiconductor material having a forbidden band width greater than that of the materials of said other layers so as to be transparent to the radiation to be detected.
3. A diode as claimed in claim 2, wherein the conductivity types of said layers are selected in such a way that the avalanche phenomenon is triggered off by the displacement of holes within said third zone.
4. A diode as claimed in claim 3, wherein the thickness of the third layer is sufficiently thin to be transparent to the radiation, the radiation being absorbed in the first layer.
5. A diode as claimed in claim 4, wherein said first layer has type n-conductivity, said second and third layers having type p-conductivity, the first layer having a doping concentration of the order of 1016 at/cm3, said second and said third layers having doping concentrations of the order of 1019 at/cm3, the thickness of the third layer being of the order of 0.1 micron.
6. A diode as claimed in claim 3, wherein said third layer is sufficiently thick to absorb the radiation to be detected.
7. A diode as claimed in claim 6, wherein the first layer has p-type conductivity, the second and third layers have type n-conductivity, the doping concentrations being of the order of 1018 at/cm3 and 1016 at/cm3, respectively.
8. A diode as claimed in claim 1, wherein the layers are made of a compound corresponding to the formula Ga1 -x Alx As.
US05/684,382 1975-05-16 1976-05-07 Avalanche photodiode Expired - Lifetime US4037244A (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
FR7515437A FR2311408A1 (en) 1975-05-16 1975-05-16 AVALANCHE PHOTODIODE
FR75.15437 1975-05-16

Publications (1)

Publication Number Publication Date
US4037244A true US4037244A (en) 1977-07-19

Family

ID=9155367

Family Applications (1)

Application Number Title Priority Date Filing Date
US05/684,382 Expired - Lifetime US4037244A (en) 1975-05-16 1976-05-07 Avalanche photodiode

Country Status (5)

Country Link
US (1) US4037244A (en)
JP (1) JPS51140587A (en)
DE (1) DE2620951A1 (en)
FR (1) FR2311408A1 (en)
GB (1) GB1509144A (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4160985A (en) * 1977-11-25 1979-07-10 Hewlett-Packard Company Photosensing arrays with improved spatial resolution
US4276099A (en) * 1978-10-11 1981-06-30 The Secretary Of State For Defence In Her Britannic Majesty's Government Of The United Kingdom Of Great Britain And Northern Ireland Fabrication of infra-red charge coupled devices
US5554882A (en) * 1993-11-05 1996-09-10 The Boeing Company Integrated trigger injector for avalanche semiconductor switch devices

Families Citing this family (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2396419A1 (en) * 1977-06-27 1979-01-26 Thomson Csf DIODE CAPABLE OF OPERATING AS EMITTER AND LIGHT DETECTOR OF THE SAME WAVELENGTH ALTERNATIVELY
JPS55162280A (en) * 1979-06-01 1980-12-17 Mitsubishi Electric Corp Photodiode
JPS5721876A (en) * 1980-07-14 1982-02-04 Canon Inc Photosensor
JPS57198668A (en) * 1981-06-01 1982-12-06 Fujitsu Ltd Light receiving element
CA1280196C (en) * 1987-07-17 1991-02-12 Paul Perry Webb Avanlanche photodiode
JP4949053B2 (en) * 2007-02-06 2012-06-06 中澤 直継 Power distribution duct

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3959646A (en) * 1973-11-28 1976-05-25 Thomson-Csf Avalanche photo-diodes

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3821777A (en) * 1972-09-22 1974-06-28 Varian Associates Avalanche photodiode

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3959646A (en) * 1973-11-28 1976-05-25 Thomson-Csf Avalanche photo-diodes

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4160985A (en) * 1977-11-25 1979-07-10 Hewlett-Packard Company Photosensing arrays with improved spatial resolution
US4276099A (en) * 1978-10-11 1981-06-30 The Secretary Of State For Defence In Her Britannic Majesty's Government Of The United Kingdom Of Great Britain And Northern Ireland Fabrication of infra-red charge coupled devices
US5554882A (en) * 1993-11-05 1996-09-10 The Boeing Company Integrated trigger injector for avalanche semiconductor switch devices

Also Published As

Publication number Publication date
JPS51140587A (en) 1976-12-03
GB1509144A (en) 1978-04-26
DE2620951A1 (en) 1976-11-25
FR2311408B1 (en) 1977-12-09
FR2311408A1 (en) 1976-12-10

Similar Documents

Publication Publication Date Title
JP3116080B2 (en) High sensitivity ultraviolet radiation detection photodiode
US3959646A (en) Avalanche photo-diodes
EP0142316A2 (en) Improved p-i-n- and avalanche photodiodes
US5075750A (en) Avalanche photodiode with adjacent layers
JPH04111479A (en) Light-receiving element
US4037244A (en) Avalanche photodiode
US5187380A (en) Low capacitance X-ray radiation detector
CA1090457A (en) Photodiode structure having an enhanced blue color response
KR950003950B1 (en) Photo-sensing device
US3812518A (en) Photodiode with patterned structure
US5459332A (en) Semiconductor photodetector device
US3745424A (en) Semiconductor photoelectric transducer
US4488038A (en) Phototransistor for long wavelength radiation
CA1243388A (en) Impurity band conduction semiconductor devices
US4816890A (en) Optoelectronic device
US20040036146A1 (en) Phototransistor device with fully depleted base region
US6081020A (en) Linear PIN photodiode
JP3047385B2 (en) Light receiving element
JPS6222473B2 (en)
JP2633912B2 (en) Semiconductor light receiving device
JP2670553B2 (en) Semiconductor light receiving / amplifying device
JPS5936437B2 (en) Semiconductor photodetector
JPS59161082A (en) Semiconductor light-receptor
JPS5912032B2 (en) light detection element
Wolfgang et al. Hybrid photomultiplier tubes using internal solid state elements